兵工学报
兵工學報
병공학보
ACTA ARMAMENTARII
2009年
7期
907-910
,共4页
肖洪%吴丁毅%刘振侠%廉筱纯
肖洪%吳丁毅%劉振俠%廉篠純
초홍%오정의%류진협%렴소순
流体力学%直接仿真的蒙特卡罗方法%稀薄气体%升阻比%临近空间%气动特性
流體力學%直接倣真的矇特卡囉方法%稀薄氣體%升阻比%臨近空間%氣動特性
류체역학%직접방진적몽특잡라방법%희박기체%승조비%림근공간%기동특성
fluid mechanics%direct simulation Monte Carlo method%rare gas%lift-to-drag ratio%near space%aerodynamic performance
运用以分子动力学为基础的直接仿真的蒙特卡罗(DSMC)方法,发展了临近空间飞行器气动性能模拟软件系统.以某型航天飞机再入大气层为例,验证了系统的有效性.对乘波构型飞行器在高度为70~100km的临近空间区域的气动性能进行了模拟,研究了稀薄气体效应对高超声速乘波构型气动特性的影响.由于70~100 km的临近空间区域处于连续介质区与温度和速度跳跃区,在DSMC的模拟中为避免模拟陷于大量的分子碰撞计算,对DSMC算法的碰撞模型和有效碰撞次数进行了改进.研究结果表明:在临近空间区域,乘波构型的升阻比特性略有下降,但仍旧保持了高升阻比的气动优势;DSMC模拟结果与NS方程模拟结果随着高度增加,两者差距逐渐增大,稀薄气体效应逐渐显著;DSMC方法的模拟中,经过多次计算,最终确认在每个网格区域内15次有效碰撞次数足以模拟气体的宏观物理特性.
運用以分子動力學為基礎的直接倣真的矇特卡囉(DSMC)方法,髮展瞭臨近空間飛行器氣動性能模擬軟件繫統.以某型航天飛機再入大氣層為例,驗證瞭繫統的有效性.對乘波構型飛行器在高度為70~100km的臨近空間區域的氣動性能進行瞭模擬,研究瞭稀薄氣體效應對高超聲速乘波構型氣動特性的影響.由于70~100 km的臨近空間區域處于連續介質區與溫度和速度跳躍區,在DSMC的模擬中為避免模擬陷于大量的分子踫撞計算,對DSMC算法的踫撞模型和有效踫撞次數進行瞭改進.研究結果錶明:在臨近空間區域,乘波構型的升阻比特性略有下降,但仍舊保持瞭高升阻比的氣動優勢;DSMC模擬結果與NS方程模擬結果隨著高度增加,兩者差距逐漸增大,稀薄氣體效應逐漸顯著;DSMC方法的模擬中,經過多次計算,最終確認在每箇網格區域內15次有效踫撞次數足以模擬氣體的宏觀物理特性.
운용이분자동역학위기출적직접방진적몽특잡라(DSMC)방법,발전료림근공간비행기기동성능모의연건계통.이모형항천비궤재입대기층위례,험증료계통적유효성.대승파구형비행기재고도위70~100km적림근공간구역적기동성능진행료모의,연구료희박기체효응대고초성속승파구형기동특성적영향.유우70~100 km적림근공간구역처우련속개질구여온도화속도도약구,재DSMC적모의중위피면모의함우대량적분자팽당계산,대DSMC산법적팽당모형화유효팽당차수진행료개진.연구결과표명:재림근공간구역,승파구형적승조비특성략유하강,단잉구보지료고승조비적기동우세;DSMC모의결과여NS방정모의결과수착고도증가,량자차거축점증대,희박기체효응축점현저;DSMC방법적모의중,경과다차계산,최종학인재매개망격구역내15차유효팽당차수족이모의기체적굉관물리특성.
Aerodynamic performance simulation software system of hypersonic waverider vehicles in near space was developed by using the direct simulation Monte Carlo(DSMC) method based on molecular dynamics. Taking a certain aerocraft as an example,the effectiveness of the system was verified. Aerodynamic performances of the vehicle at the height of 70-100 km in near space were simulated, the influence of rare gas effect on aerodynamic performance of the vehicle was studied. Collision model and effect collision number of the DSMC method were improved, in order to avoiding a large amount molecule collision calculation caused by DSMC simulation in continuous medium district and jumpiness district between temperature and velocity at the height of 70-100 km in the near space. The studied results show the characteristic of lift-to-drag ratio of the vehicle descends in near space,but it remains high lift-to-drag aerodynamic advantage;the difference of simulation results between the DSMC and NS equation increases with the height increasing and the effect of rare gas increases gradually;it is proved that fifteen effect collision number in every grid is enough to simulate the macrophysical characteristic of air in DSMC method.